A practical approach is to use a Wi‑Fi SD card such as an Eye‑Fi in the camera, paired with internet access from a phone acting as a hotspot or a standalone mobile hotspot. In that setup, the card can automatically transfer images over Wi‑Fi and, depending on configuration, upload them to an online service once connectivity is available.

The main limitation is that these systems generally still need a Wi‑Fi network and a device or service configured to receive or forward the files. Community answers also note there wasn’t a fully unified, direct camera-to-cloud workflow in this setup; some solutions were aimed at sending images to a nearby computer or photo app first.

So yes: wireless near-real-time off-site backup is possible, but typically by combining a Wi‑Fi-enabled card with a phone/hotspot and an upload service, rather than relying on a single built-in camera-to-cloud solution.